1. Preheat the oven to 350 degrees F. Butter the sides and bottom of a 9-inch springform pan with 1 teaspoon of butter.

2. Grind the chocolate wafers in a food processor into fine pieces. Add the remaining (approx. 5 tablespoons) of melted butter and 2 tablespoons of the granulated into the food processor and blend. Then pour this mixture into the springform pan.

3. Beat the cream cheese with an electric mixer at high speed until smooth and creamy, for about 5 minutes. Add in the melted chocolate and the remaining 1/2 cup granulated sugar until properly mixed. Pour the raspberry liqueur and resume beating for 4 minutes until the mixture is very smooth.

4. Set the mixer at low speed and add the eggs one at a time, beating each until mixed well. Add the heavy cream and continue beating for about half a minute.

5. Now, pour the mixture into the crust in the springform pan and bake for 50 minutes until firm. Take care not to overbake; the filling should seem soft in the middle. When done, remove cake from the oven and allow to cool.

6. Whisk the sour cream and confectioners' sugar until smooth and creamy in a small bowl. Spread this topping over the cooled cake and then refrigerate. After a minimum of 4 hours, you may remove the springform ring.

7. To serve, top the cake with the raspberries and cut it into wedges.